Tonic Water
The bitter flavor comes from quinine, the extract from the bark of the cinchona tree in South America (Chinchona spp.). Quinine is the medication that saved the world from malaria, and its addition to tonic water gave rise to that classic summer drink, the gin and tonic. (This proved to be an easy way for British colonists in India to take a mild dose of their medicine.) The drug is still found in tonic water today, although at lower doses. In fact, the quinine content in tonic water is what gives the beverage its fluorescent glow under ultraviolet light. Quinine is also found in certain brands of vermouth and bitters. Although it is perfectly safe a low doses, an overdose can cause quinism, also known as cinchonism. Symptoms include dizziness, stomach problems, tinnitus, vision problems, and cardiac symptoms. Overdoses of quinine are so risky that the FDA has issued warnings about using the malaria drug for “off label” uses like the treatment of leg cramps. Pilots in the armed forces are advised not to consume tonic water for seventy-two hours before flying and to avoid drinking more than thirty-six ounces of tonic water per day.
(from Wicked Plants by Amy Stewart)
